13. WHAT I KNOW (page 2-3)
ANSWERS
1. A
2. D
3. C
4. A
5. A
6. C
7. A
8. A
9. C
10. D
11. C
12. B
13. A
14. B
15. C
14. The world where we live
today is just a small part of
our universe. In your
previous years, you have
learned about the different
theories of the origin of the
universe that eventually led
to the formation of galaxies,
solar system and other
heavenly bodies.
15. This lesson will focus on one
of those wonderful things
present in outer space, the
stars. Although stars are
millions of light years away
from us, we can still see
them twinkling in the night
sky. Let’s find out how they
emit light and what keeps
them shining for a long
time.
16. Scientists believe that the
formation of the universe
began through the explosion
of a primordial atom which
happened 13 billion years
ago. It is known as the Big
Bang. It became a theory
that also explains the
continuous expansion of the
universe.
17.
18. Right after Big Bang, protons
and neutrons combined
together and formed light
elements Hydrogen and
Helium in the process of Big
Bang Nucleosynthesis. Other
light elements such as
Lithium and Beryllium were
also formed during this
process.
22. Have you ever wondered
what we’re made of? Would
you believe that you and me
and all of the plants and all
of the animals that we can
see are all made of the same
kind of stuff that makes up
books and rocks and
mountains and the ocean?
23. We’re all made
from the same
kind of stuff, and
we call that stuff
“m __ t __ __ __”.
29. The first path occurs
when a region of high
density in a stellar
nebula condenses
into a single point of
matter that becomes
hotter and starts to
glow.